Thigh limb and method of producing same



April 29, 1952 o. 1. FAHLSTRUM THIGH LIMB AND METHOD OF PRODUCING SAME Filed March 31, 1949 INVENTOR. 0770 lvAA/FAHAS 7790M A T TOR/V5 Y Patented Apr. 29, 1952 THIGH LIMB AND LgETHOD OF PRODUCING I Otto Ivan Fahlstriim, Stockholm, Sweden Application March 31, 1949, Serial No. 84,542

In Sweden April 29, 1944 1 Claim.

In making artificial legs a common practice has been to provide a casing to receive and support whatever stump remained of an amputated limb. Such stump casing commonly has been made of sheet metal riveted in a longitudinal seam. Attempts have been made to smooth this seam by applying to it material such as putty. Due to contraction, expansion, and wear, such seam smoothing material has disappeared after a time, causing unevenness of the casing at the seam, which unevenness caused discomfort and pain to the user.

An even greater source of diificulty and expense has been the inability to remodel the stump casing from time to time to maintain a fit of the limb stump during a period of stump shrinkage which always follows amputation, although attempts to accomplish this result have been made by removing rivets, shrinking the easing and re-riveting. This process, however}, has proved inadequate to progressive refashioning of the stump casing to fit the stump.

Another painful diificulty that could not be overcome by stump casings heretofore used has been that limb stumps develop sensitive spots, thought to be at the ends of several nerves. Contact by sensitive spots with the stump casing has proved painful in many instances and practically irremediable with stump casings heretofore in use. Development of these sensitive spots on limb stumps is not confined necessarily to recognized periods of shrinkage but may occur at any time.

Thus it has been seen that the stump casings heretofore in use, by being not readily adaptable to stump shrinkage, caused undue expense and inconvenience by necessitating prolonged hospitalization pending the fitting of a stump casing, and thereafter caused unnecessary suffering and cost by not being adaptable to the exact conformation and sensitivities of the limb stump during use after the permanent artificial limb has been procured.

The stump casing forming a base portion of an artificial limb according to the present invention eliminates all of the foregoing drawbacks by rendering it feasible to furnish a permanent artificial limb to replace a limb newly amputated, which can be remodeled economically and exactly to fit the changing conformation, and accommodate the peculiar sensitivities of the limb stump shortly after amputation, and throughout its period of use.

The stump casing according to the present invention is characterized by a smooth seamless interior surface susceptible of being worked by bulging or contracting at any desired point, or by shrinking or expanding circumferentially or longitudinally, as the case may require. It is inserted in the upper part of an artificial limb. forming the base thereof, and may be fastened firmly but changeably in place with respect to the artificial limb by means such as riveting.

The stump casing of this invention is a deformable receptacle composed of malleable metallic material, having an .ischium edge, and is produced, for instance, by draw-pressing and stamping a round sheet of such malleable material into a size most nearly fitting the limb stump concerned, and thereafter refashioning as required by hammering or other similar means of working. Similarly, the bottom of the stump casing may be shaped or cut away to any extent desired.

The stump casing finished in this way is adjusted in the usual manner to its desired position, with respect to the user, in the balance of the artificial limb,- and is fixed in that position by means of smooth headed rivets set flush with the surface of the stump casing, or other similarly easily removable and replaceable means, so that at such time as may be desirable thereafter the stump casing can be removed from the balance of the artificial limb, refashioned in any detail to produce a comfortable fit, and replaced, as often as shrinkage or other physical or neural changes of the limb stump may require this to be done.

The stump casing as the upper or base portion ofan artificial limb will be disclosed more in detail in the following specification, reference being had therein to the accompanying drawings, in which Fig. 1 shows by way of illustration a thigh stump casing at an initial stage after having been formed of a malleable sheet of metal;

Fig. 2 shows the stump casing in process of being worked, with the ischium edge roughly formed at its upper extremity;

Fig. 3, being partly broken away, shows the completed stump casing bearing the finished ischium edge and inserted in a thigh portion of an artificial leg by way of illustration.

The stump casing I according to the present invention is made in the following way:

A suitably malleable metal possessing, however, necessary rigidity and tensile strength, such as, for instance, Duralumin, is selected. A round sheet of the selected material is drawpressed and turned in a bulging lathe so as to form a stump casing l of the desired size. It will be usual to produce such stump casings of standardized and graduated sizes respectively as to diameter and length, which may be manufactored economically in quantity and carried in stock and selected by diameter and length in a particular case, according to the nearest fit that can be obtained from the standard, unaltered stump casing. Thus obtained, the stump casing is subjected to manual hammering and/or interior burnishing in order that it will give the desired amount of support at the proper points and avoid contact wherever that may be desired. The ischium edge 2 is provided at the top of the stump casing either by turning the stump casing on a bulging lathe, that is to say, by turning the stump casing on a lathe and applying to the edge where it is desired to be flared a rounded rather than a cutting instrument, with the result that the upper edge is flared outwardly in the manner desired, to afford increased support at the base of the limb stump, and hammered into the final form exactly to fit the limb stump at that time. When completed, the stump casing i is placed in the artificial limb, here illustrated as the thigh portion 3 of an artificial leg.

Thus the complete artificial limb is made ready for use until such time as limb stump changes shall dictate refashioning of the limb stump casing I. As so refashioned to the exact measurements and peculiarities of the individual limb stump, the stump casing of this invention will afford maximum comfort and durability in use until such time as changes in the encased stump shall indicaterefashioning, at which time refashioning may be accomplished, if necessary, through successive fittings, and the stump casing then replaced Within the artificial limb, whether in its original alignment or in such realigned position as experience may indicate desirable. As so employed, this invention has been found to give a degree of comfort and extent of useability never heretofore closely approached.

This application is a continuation in part of my application, Serial No. 670,649, dated May 17, 1946 and now abandoned.

I claim:

A method of making an artificial limb including a limb-stump socket adapted to be removably supported in an outer artificial limb casing and to be repeatedly reshaped to conform with changes in the shape and size of the limb stump of the wearer over a period of time Without the use of casts, molds and like pattern means, which comprises draw-pressing and stamping a continuous sheet of a malleable light-weight metal to provide a seamless sleeve, hammering said sleeve to conform the shape of said sleeve to the shape of the limb-stump, inserting said sleeve into the outer artificial limb casing, removably securing said sleeve to said casing, removing said sleeve from said casing, hammering said sleeve to shrink and deform it to a form again conforming to the shape of the limb-stump, and again removably securing said sleeve to said casing.

o'r'ro IVAN FAHLSTRDM.

REFERENCES CITED The following references-are of record in the file of this patent:

UNITED STATES PATENTS OTHER REFERENCES Die Design and Diemaking Practice, The Industrial Press, second edition, 1941; New York city; page 836, line 6 through page 840. 

